Conventional examples of this type of digital signal processing apparatus include, for example, the effector disclosed in Japanese Patent Publication No. Hei 1-19593. This effector comprises a plurality of operators such as multipliers and adders. This apparatus applies reverberation and modulation effects such as chorus, flanger, and the like, with respect to a digital musical tone signal which is generated. In this type of apparatus, during, for example, one sampling period, after modulation effects have been applied, reverberation is applied. That is to say, in this type of apparatus, in the case in which a plurality of effects are applied to a digital musical tone signal, the processing for applying the various "effects" is conducted in order and consecutively.
Accordingly, in such a conventional effector, while processing for the application of a given "effect" is being conducted, it is not possible to conduct processing for the application of a second "effect". As a result, the waiting period of the operators becomes large, and the effective efficiency of use of the operators worsens. In addition, as processes for the application of effects are executed in series, high speed processing is not possible.